Marginal Adaptation, Gap Width, and Fracture Strength of Teeth Restored With Different All-Ceramic Vs Metal Ceramic Crown Systems: An in Vitro Study

Eur J Prosthodont Restor Dent. 2016 Sep;24(3):130-137. doi: 10.1922/EJPRD_01550Monaco08.

Abstract

This study evaluated marginal adaptation before and after thermomechanical (TCML) loading, gap width and fracture strength of all-ceramic single crowns, as compared to porcelain-fused-to-metal (PFM). Thirty extracted premolars were prepared with a round shoulder of 1.0 mm depth. Specimens were restored with zirconia-ceramic (Group 1), lithium disilicate (Group 2) and metal-ceramic single crowns (Group 3). The replica of each sample was observed with a scanning electron microscope (SEM) to evaluate the crown-cement (c-c) and tooth-cement interface (t-c). After TCML, perfect margins decreased to 91.3% (c-c) and 93.9% (t-c) in Group 1, 94.6% (c-c) and 96.0% (t-c) in Group 2 and 73.5% (c-c) and 53.1% (t-c) in Group 3. The mean fracture strengths were 654.8 ± 98.1 N for Group 1, 551.3 ± 127 N for Group 2 and 501.43 ± 110.1 N for Group 3. All-ceramic systems could substitute for metal-ceramic crowns, but chipping of veneering ceramics, especially in zirconia-based crowns, should be investigated.

Keywords: All-Ceramic System; CAD/CAM System; Fracture Strength; Lithium Disilicate; Marginal Adaptation; Private-Label; Zirconia.

Publication types

  • Evaluation Study

MeSH terms

  • Crowns*
  • Dental Porcelain*
  • Dental Restoration, Permanent*
  • Humans
  • In Vitro Techniques
  • Materials Testing
  • Metal Ceramic Alloys*

Substances

  • Metal Ceramic Alloys
  • Dental Porcelain